Snubbing device for oil well tubing



Jan. 24, 1933. B. S.-MINOR SNUBBING DEhCE FOR OIL WELL TUBING Filed Oct.21, 1929 2 Sheets-Sheet 1 .2 $heets-$heet 2 Jan. 24, 1933. B. s. MINOR7' SNUBBING DEVICE FOR OIL WELL TUBING Filed Oct. 21. 1929 Patented 24,1933 BURT S. MINOR, OF 8A1! PEDRO, CALIFORNIA SN'UBBING DEVICE FOR OILWELL TUBING Application filed October 81, 1929. Serial No. 401,282.

Under certain conditions it is necessary to lower tubing into a well,for example, 1n wells which produce gas from which gasol ne isextracted, the gas condenses into gasolm-e and gradually accumulates inthe wel to such an extent that it greatly reduces or finally shuts offnatural gas pressure.

In order to withdraw this gasoline, and at the same time retain the gaspressure in the well, tubing is lowered through the control head to apoint below the liquid level, the tubing in such cases being providedwith a frangible closed end or tubing valve in order to prevent escapeof gas therethrough, hence it is necessary to force the tubing downwardlagainst the confined gas pressure until weight of the tubing overcomesresistance of the gas pressure.

In order to force the tubing downwardly an apparatus commonly known as asnubbing device is employed. Suchapparatus now 1n general use is more orless clumsy to handle requiring a considerable amount of time and laborto operate it, viz. downward movement of the tubing being effectedlntermittently by jaws engaging it whlch are pulled downwardly by cableson upward movement of the travelling block, it being necessary tomanually lift the Jaws after each 3 downwardmovement of the tubing inorder to obtain a new bight thereon, it being understood that the tubingis prevented from being forced upwardly by the gas pressure by slips inthe control head.

The object of this invention is to provide a mechanism'opcrated by fluidpressure for snubbing tubing into a well casing.

Another object of this invention is to provide a device for snubbingtubing and controlling the gas pressure in which the gas pressure fromthe well is utilized for efiecting the snubbing operation andcontrollingthe gas pressure during such operations.

A further object of this invention is to provide a device for forcingtubing downwardly through a control head by reciprocating movement.

Other objects and advantages will be apparent from the followingdescription, ref- -the tubing desi nated at T, and consists of a erencebeing had to the accompanying drawings, in which:

Fig. 1 is a side elevation of the snubbing device in operative positionon a control head ings, a pair of cylinders are designated at 10 inwhich are-positioned pistons 12 connected to rods 14 extending upwardlythrough stuff- 70 in boxes 15 on heads 16. The upper ends of cy indersare preferably screw threaded into the heads 16 as indicated at 18 whichare in turn threadedly connected to a plate 20, the lower ends of thecylinders being threaded into heads 22 which extend through openings ina plate 24. a The plate serves to hold the cylinders in fixed positionand is secured to the top flange 25 of a member 26 by bolts 27.

Packing or sealing members designated at 30 and 31 respectively areconnected to the member 26 and plate 24 between which is interposed thestationary member 34 of the snubbing device, the aforesaid member beingconnected by bolts 35 and nuts 36, the bolts passing through openings incompanion flanges 37. The plate 24 is'connected by bolts 38 to anemergency sealing member 40 which in turn is secured by bolts 41 to acontrol head :fitting 42 screw threaded to the upper end of the casingC.

From the foregoing it will be seen that the cylinders 10 are mountedparallel in spaced relation and supported on the casing through theassembly of the sealing members and the stationary member of thesnubbing device. The stationary member of the snubbing device serves toprevent upward movement of i plurality of slips 50 mounted therein, the00 encircling rods 53, the upper end .the rods projecting into openingsin the slips, the lower ends of which areplvotally mounted on pins 55extending through lugs 56 formed on the lower ends of guide blocks 57having inclined faces 58 engaged by the sl1ps as shown in Fig. 5.

Downward movement of the tubing is effected by a movable member 44 whichis actuated by admitting fluid pressure into the upper and lower ends ofthe cylinders. The movable member consists of a housing 46 having arms47 secured to the reduced upper ends 48 of the rods 14 by nuts 49. Aplurallty of slips 60 having teeth 61 adapted to engage the tubing areslidably mounted on guide blocks 62 having inclined faces 63 and rods64, the lower ends of the rods being pivotally mounted on pins 65, theupper ends of whlch extend into openings 66 in the slips, the teeth oftheslips being urged into engagement with the tubing by expansion coilsprings 68 encircling the rods.

Fluid pressure from within the casing is utilized to operate thesnubbing device, the combined area of the pistons 12 being greater thanthat of the tubing in order to overcome the resistance of the gaspressure acting thereon, it being understood that the lower end of thetubing is closed either by a frangible plug or a valve designated at V.Fluid pressure from the casing is conducted to the upper and lower endsof the cylinders through pipe lines as follows:

Pipes 70 are threaded into openings 71 in the heads 16 which communicatewith the interior of the cylinders, in a like manner pipes 72 arethreaded into openings 73 in the head 22, the pipes 70 and 71 lead to afourway valve 7 4 through pipes 75 and 76. Fluid or gas pressure fromthe casing is conveyed to the four-way valve through a pipe 78 extendingfrom the control head fitting 42. I

The four-way valve is provided with ports 80 and 81 adapted to registerwith the pipe 78 and exhaust pipe 82. When in the position shown in Fig.1 gas under pressure in the casing will pass through pipe 7 8 and port80 in the valve thence through pipes 75 and 76 into the upper ends ofthe cylinders, at the same time any gas in the opposite ends of thecylinders may pass through pipes 72, 76 and port 82 in the valve thencethrough exhaust pipe 82. By rotating the valve one quarter turn by thehandle 84 the flow of gas will be reversed, thereby raising the pistons,rods, and movable member.

From the construction it will be seen that by alternatelyadmittingpressure to each end of cylinders reciprocation of the movable member iseffected, on its downward movement the slips 60 will grip and move thetubing with it, the slips 50 in the stationary between a clicking soundwill be given, such move downwardly on the rods and blocks when engagedby a coupling designated at 86, thereby allowing it to pass, the springsreturning the slips into engagement with the tubing, the slips 60 of themovable membervwill also move downwardly on the rods and blocks whenengaged by a coupling during its upward movement.

The packing or sealin members 30, 31, and 40 are provided witl i annularpacking rings 86 formed of resilient material and serve to preventescape of gas around the tubing and are normally expanded intoengagement therewith by fluid pressure preferably from the well, thepacking rings being successively deflated and expanded (by manipulatingsuitable control valves not shown) to permit passage of a couplingduring downward movement of the tubing. It being noted that upon returnmovement of the slips 50 after a coupling has passed theresoundindicating to the operator the position'of coupling so that the packersin the sealing members 31 and 40 may be deflated to permit passagetherethrough.

In actual practice the snubbing device is operated as above describeduntil the weight of the tubing overcomes the gas pressure at which timeit will slide downwardly due to its own weight. After reaching apredetermined. "point below the fluid level the valve V is opened byrotating the tubing one quarter turn, the gas pressure will then forcethe liquid upwardly through the tubing. A frangible sealcloslng thelower end of the tubing maybe substituted for the valve V, this sealbeing broken when the tubing has been lowered to required depth as abovestated.

I claim: I

1. A snubbing device for forcing tubing into a well against confined gaspressure, comprising a plate, a cylinder secured to said plate, anddisposed at one side thereof, a relatively stationary member secured tosaid plate and extending downwardly therefrom, packing and sealingmembers carried by said stationary member, a relatively movable memberdisposed. above said plate and connected to the piston rod of saidcylinder, a tubing gripping device carried by said movable member, therebeing aligned openings in said stationary and movable members and saidplate to permit the passage of tubing therethrough, means for admittinggas pres--.

prising a late, a cylinder secured to said plate and disposed at oneside thereof, a relatively stationar member secured to said plate andextending downwardly therefrom, a relatively movable member dis osedabove said plate and connected to the plston rod of said cylinder, atubing gripping member in said movable member, there being, alignedopenings in said stationary and said movable members and said plate topermit the passage of tubing therethrough, means in said stationarymember for preventing the upward movement of tubing, packing and sealingmembers above and below said means means for admittin gas pressure fromsaid well into said cyhnder to operate said movable member, and meanswhereby said snubbing device may be secured to the control head of awell.

3. In a snubbing device for forcing tubing into a well against confinedgas pressure, upper and lower plates, a plurality of cylinders securedat t eirupper and lower ends to the upper and lower plates respectively,

a piston and piston rod in each of said cylinders, a relativelv movablemember secured to the upper ends of said piston rods, a tubing grip ingmember carried by said movable mem r, a relatively' stationary memberdisposed between saidupper and lower plates, packing and sealing memberscarried by said stationary member and secured to said upper andlowerplates, means wherebv the lower plate may be secured to the control headof 85 a well, and mears 'fof leading gas pressure to the lower and upperends of said cylinders for actuating said pistons and operating saidmovable member.

4. A snubbing device for forcing tubing 40 into a well against confinedgas pressure, up-

per and lower plates, a plurahty of cylin-.

ders secured to said cylinders and therebetween, a piston and piston rodin each of said cylinders, a relatively movable member. se-

cured to sad piston rods, a tubing gri ping member carried by saidmovable mem r, a relatively stationary member dis osed -between saldlates, packing and sealm members carried by said stationary mem r and, 5secured to said upper and lower plates, means whereby the lower platemay be secured to. the control head of a well, an emergency sealingmember disposed between the lower plate and the control'head, and meansfor leading 5 gas pressure from the well into the c lindersv to actuatethe pistons and operate t e movable member.

In testimony whereof I afiix my si ature.

.BURT 8. MI OR.

